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Office Open XML formats


ECMA-376 specifies a family of XML schemas, collectively called Office Open XML, which define the XML vocabularies for word-processing, spreadsheet, and presentation documents, as well as the packaging of documents that conform to these schemas. ECMA-376 contains 4 parts, but only part 2 (open packaging conventions) was revised in the last edition of the Standard published in December 2021.

History of ECMA-376 development

  • 2005-06: TC45 was created
  • 2005-12: TC45 had its organizational meeting in Brussels, BE
  • 2006-01: TC45 began meeting weekly via teleconference, and bi-monthly face-to-face
  • 2006-12: First edition of ECMA-376 approved
  • 2006-12: ECMA-376 submitted to ISO/IEC JTC 1 as a fast-track, by Ecma, a Category-A liaison; the Draft ISO spec became known as DIS 29500
  • 2007-02: Liaison between Ecma and ISO/IEC JTC 1/SC 34 (document formats) announced
  • 2007-03: TC45 liaison began attending SC 34 Plenary meetings
  • 2007-07: Liaison between TC45 and TC46 (XPS) announced
  • 2008-02: Ballot Resolution Meeting (BRM) on fast-track occurred in Geneva, CH
  • 2008-11: IS 29500 approved as a 4-Part standard
  • 2008-12: Second edition of ECMA-376, all Parts (which matched IS 29500:2008) approved
  • 2009-01: ISO/IEC JTC/SC 34/WG 4 met face-to-face for the first time, to start maintaining IS 29500
  • 2011-06: Third edition of ECMA-376, all Parts (which matched IS 29500:2011) approved
  • 2012-12: Fourth edition of ECMA-376, all Parts (which matched IS 29500:2012) approved
  • 2015-12: Fifth edition of ECMA-376-3 (which matched IS 29500-3:2015) approved
  • 2016-12: Fifth edition of ECMA-376-1, -4 (which matched IS 29500-1:2016, -4:2016) approved
  • 2020-02: A DIS ballot started on a new edition of ECMA-376-2/IS 29500-2
  • 2021-12: Fifth edition of ECMA-376-2 (which matched IS 29500-2:2021) approved


Since the initial submission of ECMA-376 became ISO/IEC 29500, the maintenance of the standard takes place in ISO/IEC JTC 1 SC 34/WG 4, on which Ecma TC45 is well represented. The schedule of WG 4 meetings can be found on the SC 34 website.

Current activities

TC45 works closely with WG 4 on the maintenance and evolution of all Parts of IS 29500. This involves the submission and resolution of Defect Reports (DRs), the production of Amendments (AMDs) and Technical Corrigenda (CORs), and the revision of the Parts. TC45 provides technical experts, the meeting secretary, and Project Editor for WG 4’s 29500-related work.

When any part of IS 29500 is revised, a technically equivalent revision of ECMA-376 is produced and submitted to Ecma for approval at its next General Assembly (GA).


The following organizations have participated in the work of Ecma TC45, and their contributions are gratefully acknowledged: Apple, Barclays Capital, BP, The British Library, Essilor, The Gnome Foundation, Intel, The Library of Congress, Microsoft, NextPage, Novell, Statoil, and Toshiba.


TC45 has an active liaison with ISO/IEC JTC 1/SC 34; the TC45 liaison officer is John Haug.

Office Open XML overview

White paper in English (September 2008) regarding the 2nd edition of ECMA-376 (the version that was fast-tracked to ISO/IEC JTC 1)

White paper (December 2006) in English and in other languages: Chinese, Dutch, French, German, Korean, Portuguese and Spanish regarding the 1st edition of ECMA-376

Office Open XML presentations

Office Open XML presentation by the British Library, April 2007

SNV UK14 Information meeting on ISO/IEC DIS 29500 in Olten (May 30, 2007) by Hans-Rudolf Thomann, CEO Thomann Consulting

Presentation “ECMA-376 and the evolution of Open File Formats” by Mark Lange, Senior Policy Counsel, Microsoft EMEA, May 2007

Presentation “Document Formats: Ecma Office Open XML”  by Dr. Istvan Sebestyen, Secretary General of Ecma International, May 2007

Presentation “Die Bedeutung der Standardisierung im öffentlichen Sektor” by Prof. Dr. Jürg Römer, Studiengangsleiter Wirtschaftsinformatik, Präsident eCH, May 2007